Staff: Mentor

Welcome to the PF. What is your background? What class is this a project for? What learning materials are you using to understand modulation in general, and PSK in particular? Here is a basic reference about PSK:

Staff: Mentor

thx for your reply. but i cant find the circuit. can u please send me the complete circuit instead?

Nope. You need to do the legwork -- that's what a project is for. To help you learn about the subject, and to learn how to find information and use it. I'll give you a little push in the right direction, though.... Go to www.national.com (the National Instruments website) and do a search on LM1496. That will give you several application notes, etc., on how the part is used for modulation. In case you have trouble getting there and doing the search, here's the hit list: